Various compression devices are known for applying compressive pressure to a patient's limb. These types of devices are used to assist mainly in the prevention of deep vein thrombosis (DVT), vascular disorders and the reduction of oedema. U.S. Pat. No. 6,786,879 and U.S. Patent Publication No. 2004/0111048 disclose such devices.
Compression therapy is used in the treatment of venous leg ulcers. The treatment relies on the compression achieving a reduction in oedema and improved return of blood via the venous system. This in turn reduces the residence time for blood supplied to the lower limb and the severity of ischaemic episodes within the limb that can result in tissue breakdown.
Compression of the limb in the treatment of venous leg ulcers is most usually achieved by the use of elastic bandages. Elastic bandages have the advantages that the patient can be mobile, can be treated at home and that once applied by a health care professional any removal or interference may be possible to detect. Elastic bandages do, however, have many disadvantages. They can work loose, the pressure generated by the bandage on the limb is not measured and depends on the level of skill of the health care professional applying the bandage, the level of compression is also affected by the circumference of the limb, the bandage cannot be removed and reapplied by the patient, for instance for bathing, and many patients find them unsightly, uncomfortable, hot or painful.
Compression of the limb in the treatment of venous leg ulcers can also be achieved by the use of compression stockings, although they are most often used in the prevention of leg ulcers for instance in the prevention of recurrence after an active leg ulcer has healed. Compression stockings have many of the advantages of elastic bandages, they can be used at home and the patient can be mobile. They, however, have some disadvantages. They are difficult to apply as the narrow ankle part has to be pulled over the heel, compliance with treatment is difficult to monitor as the patient may be able to remove and replace the stocking themselves and patients can find them uncomfortable.
Compression of the limb can also be achieved by a pneumatic compression device. As venous leg ulcers are most usually treated at home or in the community and the known compression devices are large, heavy and require professional supervision, their adoption for such treatment has not been widespread. The known devices used previously apply pressure to the limb through a thick cuff or cuffs which affect patient mobility and are aesthetically unacceptable to many patients. The pump which produces the compression is large and heavy and can supply fluid to the cuffs through many pipes. These characteristics make the known devices unsuitable for home use.
Pneumatic compression devices have the following advantages: They provide an effective treatment; while deflated, the inflatable cuff or cuffs are easy to apply to the patient's leg; and the pressure is more readily controlled and monitored.
Compression devices typically have inflatable sleeves and can have an associated pressure sensor which measures pressure exerted by the sleeve when in use upon the limb of a patient. The measured pressure can be used for a variety of reasons. For example, it can be used by a healthcare professional, e.g., a doctor, in order to obtain information about use of the product. This can be useful when the doctor is not in attendance while the compression device is being used. Data relating to the pressure exerted by the sleeve on the patient's limb can be stored for later analysis by the healthcare professional. Additionally, the measured pressure readings can be used by a control system of the compression device to subsequently calculate a pressure to be applied to a patient's limb. Other uses for measured pressure readings will also be apparent to a person skilled in the art. It is important that the measured pressure reading is accurate.